LeetCode26-Remove-Duplicates-from-Sorted-Array

Given a sorted array nums, remove the duplicates in-place such that
each element appear only once and return the new length.

Do not allocate extra space for another array, you must do this by
modifying the input array in-place with O(1) extra memory.

Example 1:

Given nums = [1,1,2],

Your function should return length = 2, with the first two elements of
nums being 1 and 2 respectively.

It doesn’t matter what you leave beyond the returned length. Example
2:

Given nums = [0,0,1,1,1,2,2,3,3,4],

Your function should return length = 5, with the first five elements
of nums being modified to 0, 1, 2, 3, and 4 respectively.

It doesn’t matter what values are set beyond the returned length.
Clarification:

Confused why the returned value is an integer but your answer is an
array?

Note that the input array is passed in by reference, which means
modification to the input array will be known to the caller as well.

Internally you can think of this:

// nums is passed in by reference. (i.e., without making a copy) int
len = removeDuplicates(nums);

// any modification to nums in your function would be known by the
caller. // using the length returned by your function, it prints the
first len elements. for (int i = 0; i < len; i++) {

print(nums[i]); }

利用 set 去重

public int removeDuplicates(int[] nums) {
    int len=0;
    for(int i=0;i<nums.length;i++){if(i>0 && nums[i]==nums[i-1]) continue;
        len++;
        nums[len-1]=nums[i];
    }
    return len;
}